A Flexible/Sliceable Ethernet (FlexEth for short) may be used to configure one Ethernet port as multiple virtual Ethernet ports, so that one Ethernet link is split into multiple virtual Ethernet links (a virtual Ethernet link obtained after splitting is referred to as a sub-Ethernet link). These sub-Ethernet links maybe connected to different routers or switches. During specific implementation, the sub-Ethernet links may be allocated according to a physical coding sublayer lane (PCSL for short). For example, a physical layer device that performs transmission at a rate of 100 Gbits/s (G stands for 109, s stands for second, and bits/s stands for bits per second) has 20 PCSLs. In this way, one sub-Ethernet link thereof may contain PCSLs of any quantity of 1 to 20.
When a flexible Ethernet is used, an issue that needs to be resolved is how to identify and extract a signal of a corresponding sub-Ethernet link from signals of the entire flexible Ethernet. An existing method is adding an auto-negotiation (AN for short) sublayer to a physical layer to identify a sub-Ethernet link. The AN sublayer is located below a physical coding sublayer (PCS for short) and a physical medium dependent (PMD for short) sublayer. Therefore, the AN sublayer does not process a PCSL, and can process only a physical lane (Physical Lane, corresponding to an optical lane if an optical interconnection is used).
The existing method of adding an AN sublayer is only used to negotiate a bit rate of an Ethernet link. However, the FlexEth generally uses an optical interconnection. In this case, a rate of transmitting or receiving a signal on a single optical lane is generally determinate and cannot be changed, and therefore, a bit rate of a flexible Ethernet link does not need to be negotiated. In addition, a quantity of PCSLs is not necessarily the same as a quantity of Optical Lanes. The quantity of PCSLs is not less than the quantity of Optical Lanes. In a case in which the quantity of PCSLs is greater than the quantity of Optical Lanes, adding an AN sublayer below a PMD sublayer cannot help identify which sub-Ethernet link to which a PCSL belongs. Therefore, in the prior art, the issue of how to identify and extract a signal of a corresponding sub-Ethernet link from signals of the entire flexible Ethernet basically cannot be resolved.